Pressing and packing machine for packing tobacco in portion packets



June 20, 1967 Q v 3,326,220

PRESSING AND PACKING MACHINE FOR PACKING TOBACCO IN PORTION PACKETSFiled Aug. 27, 1964 FIGQI INVENTOR ATTORNEY$ United States Patent 4,51 2Claims. (Cl. 131-111) This invention relates to pressing and packingmachines for packing tobacco in portion packets, comprising means forintermittently supplying measured portions of tobacco to a pressingchamber in which each portion is compressed by means of a ram prior tothe transfer of said portion to a package envelope.

When tobacco, especially pipe tobacco, is packed in retail packets, itis common procedure to subject a measured quantity of tobacco to apressing operation in order to form it into a desired shape dependent onthe type of package used. During its previous manufacture, the tobaccohas normally been subjected to a so-called casing or saucing treatment,which involves that different aromatic or sweetening substances, such aslicorice, molasses and extracts of prunes, etc., have been added. As aresult of such treatment the tobacco has become more or less sticky andit will, therefore, during said pressing operation have a tendency tostick to the surfaces with which it gets into contact. It has beenattempted to overcome this disadvantage by wrapping the quantity oftobacco, before the pressing operation, into a fluid-tight cover whichthus forms part of the finished package. However, such a coverrepresents a superfluous and, consequently, cost-increasing element whenthe outer package envelope, as is now usual, is made of a substantiallyfluidand air-tight material, such as for example a polyethylene pouch orbag.

It has been proposed to line the walls of the pressing chamber and thepress ram with felt and to coat said felt with parafiin wax in order tocreate a smooth surface. However, this solution has turned out to beinsufiicient for preventing a layer of casing substances and tobaccoparts from successively accumulating on and sticking to the saidsurfaces of the pressing chamber during operation of the machine, and ithas therefore in practice been necessary to stop the packing machine andclean said surfaces at relatively short intervals, about every secondhour. It has also been suggested to heat the walls of the pressingchamber in order to render the casing substances more fluid so as topermit them of running down the walls instead of sticking thereto.However, in this case it is also necessary to discontinue operation andclean the pressing chamber at intervals. Moreover, the heating of thepressing chamber involves the risk of scorching the tobacco, and saidmethod is also disadvantageous in connection with the packing of tobaccoin envelopes of polyethylene which already softens at a temperature ofabout 80 C.

The disadvantages as above indicated are obviated by the presentinvention which consists in that the machine is provided with meansadapted to cool, during operation of the machine, such walls of thepressing chamber and the ram that during the pressing operation get intocontact with the tobacco.

This simple measure has turned out to be fully sufiicient for preventingthe deposition of sticky casing substances and adhering tobacco parts onthe surfaces of the pressing chamber and of the ram, provided that thecooling of said walls is carried so far that the air adjacent said wallsis cooled below its dew point whereby its moisture content will condenseon the walls and operate as a thin lubricating film thereon. Practicalexperiences show that it is possible in this way to avoid theabove-mentioned deposits on the walls of the chamber and the ram, evenafter very prolonged operation.

According to a feature of the invention, the walls may be hollow andprovided with inlet and outlet means for a flow of coolant circulatingthrough said cavities. Hereby the substantial amount of heat generatedby the pressing of the tobacco is removed in a simple and effectivemanner. Other suitable means for cooling the walls may, however, also betaken into consideration.

This invention will now be explained in more detail with reference tothe accompanying drawings, in which FIG. 1 is a diagrammatical verticalsection through part of a pressing chamber in a pipe tobacco packingmachine according to the invention, and

FIG. 2 is a horizontal section taken on line IIII in FIG. 1.

The drawing shows a pressing chamber 1 in the upper Wall 2 of whichthere is secured a funnel or hopper 3 through which the tobacco issupplied to the pressing chamber 1. Further, the pressing chamber hastwo stationary side walls 4 and 5, a stationary front wall 6 and amovable bottom wall 7. The rear defining wall of the parallelepipedalchamber 1 is constituted by a movable press ram 8.

The ram 8 is reciprocated towards and away from the front end wall 6 bymeans of a piston rod 9 carrying a cross member 10 which is secured tothe ram 8, such as by screws 23. The piston rod 9 is guided in a sleeve11 in the stationary portion of the apparatus. To the movable bottomwall 7 there is secured a piston rod 12 which is reciprocated by meansof driving members, not shown. In FIG. 1, the bottom wall 7 is shown inits retracted position.

During operation of the packing machine of which the pressing chambershown forms part, tobacco is intermitten-tly supplied in premeasuredquantities through the funnel 3 and falls down into the pressing chamber1 when the ram 8 assumes the position shown and the bottom wall 7 hasbeen displaced to its extreme forward position in which it contacts thefront wall 6 to close the bottom of the chamber 1, i.e. to the right inFIG. 1. Next, the ram 8 is moved forward by actuation of drivingmembers, not shown, for the piston rod 9, whereby the tobacco iscompressed in the front portion of the chamber 1 against the Wall 6.Whilst the ram 8 remains in its extreme front position, the bottom wall7 is then withdrawn, i.e. to the position shown in FIG. 1, and by meansof a discharge ram 13 which is guided laterally by the front wall 6protruding past the end faces of the side walls 4 and 5, and which isdisplaceable up and down along the wall 6, the compressed quantity oftobacco is pushed down through the open bottom of the chamber into apackage envelope, not shown, for example a bag or pouch, which has inadvance been brought into position under the pressing chamber. Then, theram 13 ascends, the bottom Wall 7 is moved forward, and the ram 8 isretracted whereafter the operations described are repeated with a freshportion of tobacco.

The Walls of the pressing chamber 1 which during the pressing operationget into contact with the tobacco consist--in addition to the front wall6 and the underside of the ram 13-of two metal slabs or plates 14 and 15recessed in one each of the side walls 4 and 5' of the chamber, a metalslab or plate 16 secured to the ram 8 and a metal slab or plate 17 whichconstitutes part of the composite chamber bottom wall 7. The saidcomponents 13-17 are adapted to be cooled during operation of themachine by means of a circulating ICOOlElIlt such as brine, each of thecomponents being provided with a system of cooling channels withassociated inlet and outlet fittings.

In the vertical discharge ram 13 the said fitting for the system ofcooling channels generally designated by 18 are provided in the upperportion, not shown, of the ram. In the bottom plate 17, the fittings aremounted at the rear ends of two longitudinally extending coolingchannels 24 which at the front end of the plate communicate through atransversely extending channel 25. As far as the plates 14 and 15 areconcerned, the fittings are provided in the associated side walls 4 and5, respectively, said walls being provided with connecting channels 19leading to the actual cooling channels 26 in the plates. The plate 16 isprovided with a system of cooling channels 27 which are in communicationwith two longitudinally extending connecting channels 28 in the ram 8.The fittings, not shown, may for example be in the form of nipples whichare screwed into the cooling channels or the connecting channels,respectively, and which are externally adapted to be connected toflexible hoses, at any rate as far as the movable parts are concerned.

The parts of the pressing chamber which during operation get intocontact with the tobacco, i.e. the front wall 6, the discharge ram 13,and the plates 14-17, are preferably made of metal, amongst other thingsin order to obtain good heat-conductivity and to obtain a smoothsurface. At its outer side the front wall 6 is insulated by means of aninsulating material 20, and as far as the other walls are concerned asuitable heat insulation is provided, for example by using a poorheat-conductive material for the side walls 4 and 5, the ram 8 and aplate 21 interposed between the plate 17 and a cross-head 22, to whichthe piston rod 12 is secured. The parts 17, 21 and 22 are secured toeach other and constitute in combination the chamber bottom wall 7. Forguiding the bottom wall during its reciprocating displacement there may,at the sides of the cross-head 22, be provided rollers which are guidedin grooves at the inner sides of the walls 4 and 5.

During operation of the packing machine, the abovementioned fittingsconnected to the cooling channels 18,

24, 25, 26, and 27 are connected to an outer circulation circuit for acoolant which is cooled outside the pressing chamber, for example in acompressor cooling unit, to a suitable low temperature sufficient forensuring that the inner surfaces, facing the pressing chamber 1, of thecooled components have a temperature slightly below the dew point of theair. Thus, a thin film of water will be formed on the said surfaces ofthe pressing chamber, the press ram and the discharge ram owing to thecondensation of the air moisture, which film has turned out to functionas an excellent lubricating means that effectively prevents casingsubstances of the tobacco or tobacco parts from sticking to saidsurfaces. It may be expedient to provide for adjusting the temperatureof the coolant or brine so that in any circumstance the required coolingof the walls is ensured but so that an unnecessarily intensive coolingis avoided. An excessive cooling is unwanted both for economic reasonsand because the said lubricating effect of the condensing water vapourswill be reduced if the cooling becomes so intensive as to produce whitefrost on the walls. In a practical embodiment, it has provedadvantageous to maintain a temperature of the circulating coolant ofabout 0 C.

I claim:

1. An apparatus for intermittently pressing quantities of tobaccoparticularly pipe tobacco, comprising means defining a pressing chamber,including stationary wall members and a movable press ram, hopper meansfor supplying tobacco to said pressing chamber, means for reciprocatingsaid press ram to vary the volume of said pressing chamber and means forejecting a portion of tobacco from said pressing chamber after beingcompressed, wherein said wall members and said press ram are hollow andprovided with inlet and outlet means for circulating a coolant throughthe interior of said wall members and press ram.

2. A method for intermittently pressing quantities of tobaccoparticularly pipe tobacco with a pressing machine comprising meansdefining a pressing chamber, including stationary wall members and amovable press ram, hopper means for supplying tobacco to said pressingchamber, means for reciprocating said press ram to vary the volume ofsaid pressing chamber and means for ejecting a portion of tobacco fromsaid pressing chamber after being compressed, wherein said wall membersand said press ram are hollow and provided with inlet and outlet meansfor circulating a coolant through the interior of said wall members andpress ram, said method comprising circulating a coolant through saidinlet and outlet means at a temperature sufficient to cool the surfacesof the pressing chamber facing the tobacco to a temperature below thedew point of the air in the chamber so that condensation forms on saidsurfaces and the tendency for the tobacco to stick to said surfaces isreduced.

References Cited UNITED STATES PATENTS 1,888,805 11/1932 Peterson 13l781,979,648 11/1934 Stelzer 13179 2,899,317 8/1959 Hensgen et al. 17-32 XSAMUEL KOREN, Primary Examiner.

H. P. HEELEY, Assistant Examiner.

1. AN APPARATUS FOR INTERMITTENTLY PRESSING QUANTITIES OF TOBACCOPARTICULARLY PIPE TOBACCO, COMPRISING MEANS DEFINING A PRESSING CHAMBER,INCLUDING STATIONARY WALL MEMBERS AND A MOVABLE PRESS RAM, HOPPER MEANSFOR SUPPLYING TOBACCO TO SAID PRESSING CHAMBER, MEANS FOR RECIPROCATINGSAID PRESS RAM TO VARY THE VOLUME OF SAID PRESSING CHAMBER AND MEANS FOREJECTING A PORTION OF TOBACCO FROM SAID PRESSING CHAMBER AFTER BEINGCOMPRESSED, WHEREIN SAID WALL MEMBERS AND SAID PRESS RAM ARE HOLLOW ANDPROVIDED WITH INLET AND OUTLET MEANS FOR CIRCULATING A COOLANT THROUGHTHE INTERIOR OF SAID WALL MEMBERS AND PRESS RAM.